Dyes for keratin fibres containing 1,3-diamino-4-heteroarylbenzene derivatives and novel 1,3-diamino-4-heteroarylbenzene derivatives

ABSTRACT

Colorants for keratin fibers containing 1,3-diamino-4-heteroarylbenzene derivatives of general formula (I) or the physiologically tolerated salts thereof  
                 
 
     as well as novel 1,3-diamino-4-heteroarylbenzene derivatives.

[0001] The invention relates to agents for oxidative dyeing of keratinfibers, particularly human hair, based on a developer/couplercombination containing as the coupler a 1,3-diamino-4-heteroarylbenzenederivative, as well as to novel 1,3-diamino-4-heteroarylbenzenederivatives.

[0002] In the area of keratin fiber dyeing, particularly hair dyeing,oxidation dyes have attained substantial importance. In this case, thecoloration is produced by reaction of certain developers with certaincouplers in the presence of an appropriate oxidant. Suitable developersare, in particular, 2,5-diaminotoluene, 2,5-diaminophenylethyl alcohol,p-aminophenol, 1,4-diaminobenzene and4,5-diamino-1-(2′-hydroxyethyl)pyrazole and suitable couplers are, forexample, resorcinol, 2-aminoresorcinol, 1-naphthol, 3-aminophenol,m-phenylenediamine, 2-amino-4-(2′-hydroxyethyl)aminoanisole,1,3-diamino-4-(2′-hydroxyethoxy)benzene and 2,4-diamino-5-fluorotoluene.

[0003] The oxidation dyes used for dyeing human hair must meet numerousrequirements in addition to that of being able to produce colorations ofthe desired intensity. For example, these dyes must be harmless from atoxicological and dermatological standpoint, and the hair colorationsobtained must have good light fastness, resistance to permanent waving,acid fastness and rubbing fastness. In any case, however, in the absenceof exposure to light, rubbing and chemicals such colorations must remainstable over a period of at least 4 to 6 weeks. Moreover, by combiningappropriate developers and couplers, it must be possible to create awide range of different color shades.

[0004] Attempts have already been made to improve the properties ofm-phenylenediamines by introduction of substituents. In this respect,the reader is referred to German Unexamined Patent Application DE-OS 3028 131 which, among other things, describes colorants containing ascouplers special m-phenylenediamines alkyl-substituted in the4-position.

[0005] The hitherto known colorants, however, do not fully meet allrequirements placed on colorants. Hence, a need continued to exist fornovel couplers capable of meeting the aforecited requirement to a majorextent.

[0006] We have now found that by use of 1,3-diamino-4-heteroarylbenzenederivatives of general formula (I) it is possible to achieve intense,stable blue color shades in addition to natural, purple or violet ones.

[0007] Hence, the object of the present invention is an agent foroxidative dyeing of keratin fibers, for example wool, furs, feathers orhair, particularly human hair, based on a developer/coupler combinationcontaining as the coupler at least one 1,3-diamino-4-heteroarylbenzenederivative of formula (I) or a physiologically tolerated salt thereof,

[0008] wherein

[0009] X1 denotes sulfur, oxygen, C—R3 or N—R2;

[0010] X2 denotes nitrogen or C—R4;

[0011] X3 denotes sulfur, nitrogen, oxygen, CR-5 or N—R2;

[0012] R1, R3, R4 and R5 can be equal or different and independently ofeach other denote hydrogen, a halogen atom (fluorine, chlorine, bromineor iodine), a cyano group, a C₁-C₄-alkoxy group, a C₁-C₆-alkyl group, aC₁-C₄-alkylthioe ther group, a mercapto group, a nitro group, an aminogroup, a C₁-C₄-monoalkylamino group, a di(C₁-C₄)alkylamino group, adi(C₁-C₄-hydroxyalkyl)amino group, a C₁-C₄-hydroxyalkylamino group, atrifluoromethane group, a —C(O)CH₃ group, a —C(O)CF₃ group, an —Si(CH₃)₃group, a C₁-C₄-hydroxyalkyl group or a C₃-C₄-dihydroxyalkyl group;

[0013] R2 denotes hydrogen, a C₁-C₆-alkyl group, a C₂-C₄-hydroxyalkylgroup, a phenyl group or an acetyl group;

[0014] wherein at least one and at the most two X1 to X3 groups denoteC—R3, or C—R4 or C—R5, and at the most one of the X1 to X3 groupsdenotes sulfur, oxygen or N—R2.

[0015] Compounds of formula (I) are, for example:

[0016] 1,3-diamino-4-(2-thiophenyl)benzene,1,3-diamino-4-(3-thiophenyl)benzene,1,3-diamino-4-(1-methyl-1H-2-pyrrolyl)benzene,1,3-diamino-4-(2-pyrrolyl)benzene, 1,3-diamino-4-(2-furyl)benzene,1,3-diamino-4-(2-thiazolyl)benzene,1,3-diamino-4-(1H-2-imidazolyl)benzene, 1,3-diamino-4-(3-furyl)benzene,1,3-diamino-4-(3-amino-2-thiophenyl)benzene,1,3-diamino-4-(3-chloro-2-thiophenyl)benzene,1,3-diamino-4-(3-methyl-2-thiophenyl)benzene,1,3-diamino-4-(3-nitro-2-thiophenyl)-benzene,1,3-diamino-4-(4-amino-2-thiophenyl)benzene,1,3-diamino-4-(4-chloro-2-thiophenyl)benzene,1,3-diamino-4-(4-methyl-2-thiophenyl)benzene,1,3-diamino-4-(4-nitro-2-thiophenyl)benzene,1,3-diamino-4-(5-amino-2-thiophenyl)benzene,1,3-diamino-4-(5-chloro-2-thiophenyl)benzene,1,3-diamino-4-(5-methyl-2-thiophenyl)benzene,1,3-diamino-4-(5-nitro-2-thiophenyl)benzene,1,3-diamino-(2-amino-3-thiophenyl)benzene,1,3-diamino-(2-chloro-3-thiophenyl)benzene,1,3-diamino-(2-methyl-3-thiophenyl)benzene,1,3-diamino-(2-nitro-3-thiophenyl)benzene,1,3-diamino-(4-amino-3-thiophenyl)benzene,1,3-diamino-(4-chloro-3-thiophenyl)benzene,1,3-diamino-(4-methyl-3-thiophenyl)benzene,1,3-diamino-(4-nitro-3-thiophenyl)benzene,1,3-diamino-(5-amino-3-thiophenyi)benzene,1,3-diamino-(5-chloro-3-thiophenyl)benzene,1,3-diamino-(5-methyl-3-thiophenyl)benzene and1,3-diamino-(5-nitro-3-thiophenyl)benzene.

[0017] Preferred compounds of formula (I) are those wherein (i) X1 or X3denotes sulfur, X2 denotes C—R4 and X3 denotes C—R5 or X1 denotes C—R3;or (ii) X1 or X3 stands for sulfur, X2 stands for C—R4 and X3 stands forC—R5 or X1 stands for C—R3, and at least two of the R1, R3, R4 and R5groups denote hydrogen.

[0018] Particularly preferred are the following1,3-diamino-4-heteroarylbenzene derivatives:1,3-diamino-4-(2-thiophenyl)benzene, 1,3-diamino-4-(3-thiophenyl)benzeneand the physiologically tolerated salts thereof.

[0019] The compounds of formula (I) can be used as free bases or in theform of their physiologically tolerated salts with inorganic or organicacids, for example hydrochloric acid, sulfuric acid, phosphoric acid,acetic acid, propionic acid, lactic acid or citric acid.

[0020] The 1,3-diamino-4-heteroarylbenzene derivatives of formula (I)are contained in the colorant of the invention in a total amount ofabout 0.005 to 20 wt. %, an amount of about 0.01 to 5 wt. % andparticularly 0.1 to 2.5 wt. % being preferred.

[0021] Suitable developers are all developers known to be used for suchcolorants, for example 1,4-diaminobenzene (p-phenylenediamine),1,4-diamino-2-methylbenzene (p-toluylenediamine),1,4-diamino-2,6-dimethylbenzene, 1,4-diamino-3,5-diethylbenzene,1,4-diamino-2,5-dimethylbenzene, 1,4-diamino-2,3-dimethylbenzene,2-chloro-1,4-diaminobenzene, 1,4-diamino-2-(2-thiophenyl)benzene,1,4-diamino-2-(3-thiophenyl)benzene, 1,4-diamino-2-(3-pyridinyl)benzene,2,5-diaminobiphenyl, 1,4-diamino-2-methoxymethylbenzene,1,4-diamino-2-aminomethylbenzene, 1,4-diamino-2-hydroxymethylbenzene,1,4-diamino-2-(2-hydroxyethoxy)benzene, 1-(2,5-diaminophenyl)-ethanol,2-[2-(acetylamino)ethoxy]-1,4-diaminobenzene, 4-phenylaminoaniline,4-dimethylaminoaniline, 4-diethylaminoaniline, 4-dipropylaminoaniline,4-[ethyl-(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)-amino]-2-methylaniline,4-[(2-methoxyethyl)amino]aniline, 4-[(3-hydroxypropyl)amino]-aniline,4-[(2,3-dihydroxypropyl)amino]aniline,1,4-diamino-2-(2-hydroxyethyl)benzene,1,4-diamino-2-(1-methylethyl)benzene,1,3-bis[(4-aminophenyl)(2-hydroxyethyl)amino]-2-propanol,1,4-bis[(4-amino-phenyl)amino]butane,1,8-bis(2,5-diaminophenoxy)-3,6-dioxaoctane, 4-aminophenol,4-amino-3-methylphenol, 4-amino-3-(hydroxymethyl)phenol,4-amino-3-fluorophenol, 4-methylaminophenol,4-amino-2-(aminomethyl)phenol, 4-amino-2-(hydroxymethyl)phenol,4-amino-2-fluorophenol, 4-amino-2-[(2-hydroxyethyl)amino]methylphenol,4-amino-2-methylphenol, 4-amino-2-methoxymethyl)phenol,4-amino-2-(2-hydroxyethyl)phenol, 5-aminosalicylic acid,2,5-diaminopyridine, 2,4,5,6-tetraaminopyrimidine,2,5,6-triamino-4-(1H)-pyrimidone,4,5-diamino-1-(2-hydroxyethyl)-1H-pyrazole,4,5-diamino-1-(1-methylethyl)-1H-pyrazole,4,5-diamino-1-[(4-methylphenyl)methyl]-1H-pyrazole,1-[(4-chlorophenyl)methyl]-4,5-diamino-1H-pyrazole,4,5-diamino-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole, 2-aminophenol,2-amino-6-methylphenol and 2-amino-5-methylphenol.

[0022] The colorant of the invention can optionally also contain othercouplers, for example 2,6-diaminopyridine,2-amino-4-[(2-hydroxyethyl)amino]anisole,2,4-diamino-1-fluoro-5-methylbenzene,2,4-diamino-1-methoxy-5-methylbenzene, 2,4-diamino-1-ethoxy-5-methylbenzene, 2,4-diamino-1-(2-hydroxyethoxy)-5-methylbenzene,2,4-[(2-hydroxyethyl)amino]-1,5-dimethoxybenzene,2,3-diamino-6-methoxypyridine,3-amino-6-methoxy-2-(methylamino)pyridine,2,6-diamino-3,5-dimethoxypyridine, 3,5-diamino-2,6-dimethoxypyridine,1,3-diaminobenzene, 2,4-diamino-1-(2-hydroxyethoxy)benzene,2,4-diamino-1,5-di(2-hydroxyethoxy)benzene,1-(2-aminoethoxy)-2,4-diaminobenzene,2-amino-1-(2-hydroxyethoxy)-4-methylaminobenzene,2,4-diaminophenoxyacetic acid, 3-di[(2-hydroxyethyl)amino]aniline,4-amino-2-di[(2-hydroxyethyl)amino]-1-ethoxybenzene,5-methyl-2-(1-methylethyl)phenol, 3-[(2-hyd roxyethyl)amino]aniline,3-[(2-aminoethyl)amino]aniline, 1,3-di(2,4-diaminophenoxy)propane,1,3-di(2,4-diaminophenoxy)methane, 1,3-diamino-2,4-dimethoxybenzene,2,6-bis-(2-hydroxyethyl)aminotoluene, 4-hydroxyindole,3-dimethylaminophenol, 3-diethylaminophenol, 5-amino-2-methylphenol,5-amino-4-fluoro-2-methylphenol, 5-amino-4-methoxy-2-methylphenol,5-amino-4-ethoxy-2-methylphenol, 3-amino-2,4-dichlorophenol,5-amino-2,4-dichlorophenol, 3-amino-2-methylphenol,3-amino-2-chloro-6-methylphenol, 3-aminophenol,2-[(3-hydroxyphenyl)amino]acetamide,5-[(2-hydroxyethyl)amino]-2-methylphenol,3-[(2-hydroxyethyl)aminolphenol, 3-[(2-methoxyethyl)amino]phenol,5-amino-2-ethylphenol, 2-(4-amino-2-hydroxyphenoxy)ethanol,5-[(3-hydroxypropyl)amino]-2-methylphenol, 3-[(2,3-dihydroxypropyl)amino]-2-methylphenol,3-[(2-hydroxyethyl)amino]-2-methylphenol, 2-amino-3-hydroxypyridine,5-amino-4-chloro-2-methylphenol, 1-naphthol₁, 1,5-dihydroxynaphthalene,1,7-dihydroxynaphthalene, 2,3-d ihydroxynaphthalene,2,7-dihydroxynaphthalene, 2-methyl-1-naphthol acetate,1,3-dihydroxybenzene, 1-chloro-2,4-dihydroxybenzene,2-chloro-1,3-dihydroxybenzene,1,2-dichloro-3,5-dihydroxy-4-methylbenzene,1,5-dichloro-2,4-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene,3,4-methylenedioxyphenol, 3,4-methylenedioxyaniline,5-[(2-hydroxyethyl)amino]-1,3-benzodioxole,6-bromo-1-hydroxy-3,4-methylenedioxybenzene, 3,4-diaminobenzoic acid,3,4-dihydro-6-hydroxy-1,4(2H)benzoxazine,6-amino-3,4-dihydro-1,4(2H)benzoxazine, 3-methyl-1-phenyl-5-pyrazolone,5, 6-dihydroxyindole, 5, 6-dihydroxyindoline, 5-hydroxyindole,6-hydroxyindole, 7-hydroxyindole and 2,3-indolinedione.

[0023] The couplers and developers can be present in the colorant of theinvention either individually or in admixture with one another, thetotal amount of couplers and developers in the colorant of the inventioneach being about 0.005 to 20 wt. % preferably about 0.01 to 5.0 wt.°/andparticularly 0.1 to 2.5 wt. % (based on the total amount of colorant).The total amount of the developer-coupler combination contained in thecolorant described herein is preferably about 0.01 to 20 wt. %, anamount of about 0.02 to 10 wt. % and especially 0.2 to 6 wt. % beingparticularly preferred. In general, the developer and the coupler areused in approximately equimolar amounts; however, it is notdisadvantageous if the developer is present in a certain excess ordeficiency (for example in a coupler: developer ratio of 1:2 to 1:0.5).

[0024] Moreover, the colorant of the invention can also contain otherdye components, for example 6-amino-2-methylphenol and2-amino-5-methylphenol, as well as common anionic, cationic,zwitterionic or nonionic direct dyes, for example triphenylmethane dyessuch as 4-[(4′-aminophenyl)-(4′-imino-2″, 5″-cyclohexadien-1 ″-ylidene)methyl]-2-methylaminobenzene monohydrochloride (Color Index (C.I.] 42510) and4-[(4′-amino-3′-mthylphenyl)-(4″-imino-3″-methyl-2″,5″-cyclohexadien-1″-ylidene) methyl]-2-methylarninobenzene monohydrochloride (C.I. 42520), aromatic nitro dyes such as 4-(2′-hydroxyethyl)aminonitrotoluene,2-amino-4,6-dinitrophenol, 2-amino-5-(2′-hydroxyethyl)aminonitrobenzene,2-chloro-6-(ethylamino)-4-nitrophenol,4-chloro-N-(2-hydroxyethyl-2-nitroaniline,5-chloro-2-hydroxy-4-nitroaniline, 2-amino-4-chloro-6-nitrophenol and1-(2′ureidoethyl)amino-4-nitrobenzene, azo dyes such as, for example,sodium 6-[(4′-aminophenyl)azo]-5-hydroxynaphthalene-1-sulfonate (C.I. 14805) and disperse dyes, for example 1,4-diaminoanthraquinone and1,4,5,8-tetraaminoanthraquinone. The colorants of the invention cancontain the aforesaid dye components in an amount from about 0.1 to 4wt. %.

[0025] The couplers and developers as well as the other dye components,provided they are bases, can, of course, also be used in the form oftheir physiologically tolerated salts with organic or inorganic acids,for example hydrochloric acid or sulfuric acid, or—if they containaromatic OH groups—in the form of their salts with bases, for example asalkali metal phenolates.

[0026] Moreover, if the colorants of the invention are to be used forcoloring hair, they can contain other common cosmetic agents, forexample antioxidants such as ascorbic acid, thioglycolic acid or sodiumsulfite, as well as perfume oils, complexing agents, wetting agents,emulsifiers, thickeners and hair-care agents.

[0027] The colorant of the invention can be in the form of, for example,a solution, particularly an aqueous or aqueous-alcoholic solution. Aparticularly preferred formulation form, however, is a cream, gel oremulsion. Such a composition consists of a mixture of the dye componentsand the usual additives employed for such compositions.

[0028] Common additives to solutions, creams, emulsions or gels are, forexample solvents such as water, lower aliphatic alcohols, for exampleethanol, propanol or isopropanol, glycerol or glycols such as1,2-propylene glycol, moreover wetting agents or emulsifiers from theclasses of anionic, cationic, amphoteric or nonionic surface-activeagents, for example fatty alcohol sulfates, ethoxylated fatty alcoholsulfates, alkylsulfonates, alkylbenzenesulfonates,alkyltrimethylammonium salts, alkylbetaines, ethoxylated fatty alcohols,ethoxylated nonylphenols, fatty acid alkanolamides and ethoxylated fattyesters, furthermore thickeners such as the higher fatty alcohols,starch, cellulose derivatives, petrolatum, paraffin oil and fatty acids,also hair-care agents, such as cationic resins, lanolin derivatives,cholesterol, pantothenic acid and betaine. The cited constituents areused in amounts commonly employed for such purposes, for example thewetting agents and emulsifiers at a concentration of about 0.5 to 30 wt.%, the thickeners in an amount from about 0.1 to 25 wt. % and thehair-care agents at a concentration from about 0.1 to 5 wt. %.

[0029] Depending on the composition, the colorant of the invention canbe weakly acidic, neutral or alkaline. In particular, it has a pH ofabout 6.5 to 11.5. Adjustment to a basic pH is preferably done withammonia, but it can also be done with an organic amine, for examplemonoethanolamine and triethanolamine, or with an inorganic base such assodium hydroxide and potassium hydroxide. Suitable for adjustment to anacidic pH are inorganic or organic acids, for example phosphoric acid,acetic acid, citric acid or tartaric acid.

[0030] For oxidative dyeing of hair, the afore-described colorants aremixed with an oxidant just before use, and the resulting mixture isapplied to hair in an amount sufficient for the hair-dyeing treatment,in general about 50 to 200 grams, depending on the hair fullness. Theready-to-use oxidation dye obtained by mixing with the oxidantpreferably has a pH of 6.5 to 11.5.

[0031] Suitable oxidants for developing the hair coloration are mainlyhydrogen peroxide or its products of addition to urea, melamine, sodiumborate or sodium carbonate, in the form of a 3-12%, preferably 6%aqueous solution, atmospheric oxygen also being suitable. When a 6%hydrogen peroxide solution is used as oxidant, the weight ratio of haircolorant to oxidant is from 5:1 to 1:2, but preferably 1:1. Largeramounts of oxidant are used primarily at higher dye concentrations inthe hair colorant or when strong bleaching of the hair is wanted at thesame time. The mixture is allowed to act on the hair at 15 to 50° C. forabout 10 to 45 min, preferably 30 min, after which the hair is rinsedwith water and dried. Optionally, following this rinsing, the hair iswashed with a shampoo and optionally post-rinsed with a weak organicacid, for example citric acid or tartaric acid. The hair is then dried.

[0032] The colorants of the invention containing a1,3-diamino-4-heteroarylbenzenederivative of formula (I) as coupler givehair colorations of excellent color fastness, particularly in terms oflight fastness, wash fastness and rubbing fastness. As far as the dyeingproperties are concerned, the hair colorants of the invention, dependingon the kind and composition of the dye component, provide a wide rangeof different color shades from blond to brown, purple, violet and evenblue and black, depending on the developer-coupler combination. Theintense, stable blue color shades obtainable in this manner areparticularly noteworthy. In particular, the very good coloringproperties of the hair colorant of the present invention also manifestthemselves in that these colorants make it possible to dye graying hair,chemically not previously damaged, without any problems and with goodcovering power.

[0033] The 1,3-diamino-4-heteroarylbenzene derivatives of formula (I)can be prepared by known methods of synthesis, for example by methodssimilar to those described in the following examples.

[0034] The 1,3-diamino-4-heteroarylbenzene derivatives of formula (I)are readily water-soluble and afford colorations, particularly in theblue range of shades, with excellent color fastness, particularly interms of light fastness, wash fastness and rubbing fastness. Moreover,they have outstanding storage stability, particularly as constituents ofthe hereindescribed oxidation colorants.

[0035] Hence, another object of the present invention are1,3-diamino-4-heteroarylbenzene derivatives of general formula (I)wherein X2 is not nitrogen when X1 denotes sulfur.

[0036] The following examples illustrate the object of the invention ingreater detail without limiting its scope.

EXAMPLES Example 1

[0037] A. Synthesis of tert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate

[0038] A solution of 6.0 g (33.7 mmoles) of N-bromosuccinimide in 50 mLof 1,2-dimethoxyethane was added dropwise to a suspension of 10 g (32.4mmoles) of tert.butyl (3-tert.butoxycarbonylaminophenyl)carbamate at 0°C. over a period of 2 hours. The reaction mixture was allowed to agitatefor an additional 2 hours. At the end of the reaction, the reactionmixture was poured into 300 mL of water, which produced a precipitate.The precipitate was filtered off and washed with water.

[0039] This gave 11 g (94% of the theoretical) of tert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate.

[0040]¹H-NMR (300 MHz, DMSO-D6: δ=9.51 (s,1H), 8.43 (s,1H), 7.89 (s,1H),7.47 (d, 1H), 7.18 (d, 1H), 1.47 (d, 18H).

[0041] B. Synthesis of tert.butyl3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl-[1,3,2]dioxa-2-borolanyl)phenylCarbamate

[0042] 210 mL of degassed dioxane was added to a mixture of 7.8 g (20.2mmoles) of tert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate from step A, 12.8 g(50.6 mmoles) of4,4,4′,4′,5,5,5′,5′-octamethyl[2,2′]bis([1,3,2]dioxaborinanyl), 2 g (2.9mmoles) ofdichloro-[1,1′-bis(diphenylphospino)ferrocene]palladium[(PdCl₂ (dppf)]and 6.2 g (63.2 mmoles) of potassium acetate under argon. The mixturewas allowed to agitate 26 h at 80° C., and to it was then added amixture of 4.2 g (16.9 mmoles) of diboronpinacole ester and 700 mg (0.95mmole) of PdCl₂ (dppf). The reaction mixture was allowed to agitate foran additional 14 h at 80° C., after which it was poured into water andthe resulting mixture was extracted with ethyl acetate. The organicphase was then washed with saturated aqueous sodium chloride solution,dried over sodium sulfate, filtered and the filtrate evaporated todryness. The resulting crude product was purified on deactivatedsilicate gel with hexane/ethyl acetate (1:1). This gave 6.20 g (71% ofthe theoretical) of tert.butyl3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl[1,3,2]dioxa-2-borolanyl)phenylcarbamate.

[0043] C. Synthesis of 4-heteroaryl-1,3-diaminobenzenes

[0044] 0.09 g (0.0002 mole) of tert.butyl3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethylf[,3,2]dioxa-2-borolanyl)phenylcarbamate from step B and 0.0004 mole of the appropriate bromoderivative were dissolved in 10 mL of 1,2-dimethoxyethane. Then, 0.01 g(0.000005 mole) of tetrakis-(triphenylphosphine)palladiumand 0.26 mL of2N potassium carbonate solution were added, and the reaction mixture washeated to 80° C. At the end of the reaction, the reaction mixture waspoured into 10 mL of ethyl acetate and the organic phase was extractedwith dilute sodium hydroxide solution and then dried over magnesiumsulfate. The solvent was distilled off in a rotary evaporator, and theresidue was purified on silica gel with petroleum ether/ethyl acetate(9:1). The product thus obtained was dissolved in 4 mL of ethanol andheated to 50° C. To prepare the hydrochloride, 1.5 mL of a 2.9 molarethanolic solution of hydrochloric acid was added dropwise. Theprecipitate was filtered off, washed twice with 1-mL portions of ethanoland then dried.

[0045] a) 1,3-Diamino-4-(2-thiophenyl)benzene Hydrochloride

[0046] Bromo derivative used: 2-bromothiophene

[0047] Mass spectrum: MH+191(50)

[0048] b) 1,3-Diamino-4-(3-methyl-2-thiophenyl)benzene Hydrochloride

[0049] Bromo derivative used: 2-bromo-3-methylthiophene

[0050] Mass spectrum: MH+205(80)

[0051] c) 1,3-Diamino-4-(5-nitro-2-thiophenvl)benzene Hydrochloride

[0052] Bromo derivative used: 2-bromo-5-nitrothiophene

[0053] Mass spectrum: MH+236(100)

[0054] d) 1,3-Diamino-4-(2-thiazolyl)benzene

[0055] Bromo derivative used: 2-bromothiazole

[0056] Mass spectrum: MH+192(100)

Examples 2 to 5 Hair Colorants

[0057] Hair colorant solutions having the following composition wereprepared: 1.25 mmoles of coupler of formula (I) according to Table 11.25 mmoles of developer according to Table 1 1.0 g of potassium oleate(8% aqueous solution) 1.0 g of ammonia (22% aqueous solution) 1.0 g ofethanol 0.3 g of ascorbic acid to 100.0 g water

[0058] Just before use, 50 g of the foregoing coloring solution wasmixed with 50 g of a 6% aqueous hydrogen peroxide solution. The mixturewas then applied to bleached hair. After an exposure time of 30 min at40° C., the hair was rinsed with water, washed with a commercial shampooand dried. The resulting color shades are presented in Table 1. TABLE 1Developer* III IV II 2,5-di- 4,5-diamino- I 2,5-di- amino- 1-(2′-hy- Ex-Coupler of 1,4-di- aminoto- phenyl- droxyethyl)- ample Formula(I) amino-luene ethanol pyrazole No. as per benzene sulfate sulfate sulfate 2.Example 1a dark-blue dark-blue dark-blue purple 3. Example 1b dark-bluedark-blue dark-blue purple 4. Example 1c dark-blue dark-blue dark-bluepurple 5. Example 1d gray light-gray light-gray light-gray

Examples 6 to 11 Hair Colorants

[0059] Hair colorant solutions of the following composition wereprepared: X g of 1,3-diamino-4-heteroarylbenzene (coupler K1 of formula(I) as per Table 4) U g of developer E8 to E15 as per Table 2 Y g ofcoupler K11 to K36 as per Table 4 Z g of direct dye D1 to D3 as perTable 3 10.0 g of potassium oleate (8% aqueous solution) 10.0 g ofammonia (22% aqueous solution) 10.0 g of ethanol 0.3 g of ascorbic acidto 100.0 g water

[0060] Just before use, 30 g of the foregoing coloring solution wasmixed with 30 g of a 6% aqueous solution of hydrogen peroxide. Themixture was then applied to bleached hair. After an exposure time of 30min at 40° C., the hair was rinsed with water, washed with a commercialshampoo and dried. The coloring results are presented in Table 5. TABLE2 Developers E8 1,4-diaminobenzene E9 2,5-diaminophenylethanol sulfateE10 3-methyl-4-aminophenol E11 4-amino-2-aminomethylphenoldihydrochloride E12 4-aminophenol E13N,N-bis(2′-hydroxyethyl)-p-phenylenediamine sulfate E144,5-diamino-1-(2′-hydroxyethyl)pyrazole sulfate E15 2,5-diaminotoluenesulfate

[0061] TABLE 3 Direct Dyes D1 2,6-diamino-3-[(3-pyridinyl)azo]pyridineD2 6-chloro-2-ethylamino-4-nitrophenol D3 2-amino-6-chloro-4-nitrophenol

[0062] TABLE 4 Couplers K1 1,3-diamino-4-(2-thiophenyl)benzenehydrochloride K11 1,3-diaminobenzene K122-amino-4-(2′-hydroxyethyl)aminoanisole sulfate K131,3-diamino-4-(2′-hydroxyethoxy)benzene sulfate K142,4-diamino-5-fluorotoluene sulfate K153-amino-2-methylamino-6-methoxypyridine K163,5-diamino-2,6-dimethoxypyridine dihydrochloride K172,4-diamino-5-ethoxytoluene sulfate K18 N-(3-dimethylamino)phenylureaK19 1,3-bis(2,4-diaminophenoxy)propane tetrahydrochloride K213-aminophenol K22 5-amino-2-methylphenol K233-amino-2-chloro-6-methylphenol K24 5-amino-4-fluoro-2-methylphenolsulfate K25 1-naphthol K26 1-acetoxy-2-methylnaphthalene K311,3-dihydroxybenzene K32 2-methyl-1,3-dihydroxybenzene K331-chloro-2,4-dihydroxybenzene K344-(2′-hydroxyethyl)amino-1,2-methylenedioxybenzene.HCl K353,4-methylenedioxyphenol K36 2-amino-5-methylphenol

[0063] TABLE 5 Hair Colorants Example No. 6 7 8 9 10 11 Dyes (Amount ofdye in grams) K1 0.1  0.12 0.05 0.07 0.10 0.12 E8 0.30 E9 0.25 0.3  E150.25 0.3  0.25 K12 0.05 K13 0.05 K31 0.20 0.15 0.20 0.10 K32 0.20 0.100.10 K33 0.20 K21 0.05 K22 0.05 K23 0.05 0.10 0.10 0.10 Coloring blondblond blond blond blond blond result

Examples 13 to 17 Hair Colorants

[0064] Dye carriers in cream form and having the following compositionwere prepared: X g of 1,3-diamino-4-heteroarylbenzene (coupler K1 offormula (I) as per Table 4) U g of developer E8 to E15 as per Table 2 Yg of coupler K11 to K36 as per Table 4 Z g of direct dye D2 as per Table3 15.0 g of cetyl alcohol 0.3 g of ascorbic acid 3.5 g of sodium laurylalcohol diethylene glycol ether sulfate, 28% aqueous solution 3.0 g ofammonia, 22% aqueous solution 0.3 g of sodium sulfite, anhydrous to 100g water

[0065] Just before use, 30 g of the foregoing coloring cream was mixedwith 30 g of a 6% aqueous solution of hydrogen peroxide. The mixture wasthen applied to the hair. After an exposure time of 30 min at 40° C.,the hair was rinsed with water, washed with a commercial shampoo anddried. The coloring results are shown in Table 6. TABLE 6 Hair ColorantsExample No. 12 13 14 15 16 17 Dyes (Amount of dye in grams) K1 0.6 1.31.15 0.15 0.15 0.15 E8 1.5 E13 1.6 0.7  E15 1.8  0.7  0.7  K12 0.6 K31 1.10  1.10 1.10 0.40 0.40 0.40 K23 0.05 0.10 0.10 0.10 D2 0.10 0.100.10 Coloring black black black brown brown brown results

1. Agent for oxidative dyeing of keratin fibers based on adeveloper/coupler combination, characterized in that it contains as thecoupler at least one 1,3-diamino-4-heteroarylbenzene derivative offormula (I) or a physiologically tolerated salt thereof,

wherein X1 denotes sulfur, oxygen, C—R3 or N—R2; X2 denotes nitrogen orC—R4; X3 denotes sulfur, nitrogen, oxygen, CR-5 or N—R2; R1, R3, R4 andR5 can be equal or different and independently of each other denotehydrogen, a halogen atom (fluorine, chlorine, bromine or iodine), acyano group, a C₁-C₄-alkoxy group, a C₁-C₆-alkyl group, aC₁-C₄-alkylthioether group, a mercapto group, a nitro group, an aminogroup, a C₁-C₄-monoalkylamino group, a di(C₁-C₄)alkylamino group, adi(C₁-C₄-hydroxyalkyl)amino group, a C₁-C₄-hydroxyalkylamino group, atrifluoromethane group, a —C(O)CH₃ group, a —C(O)CF₃ group, an —Si(CH₃)₃group, a C₁-C₄-hydroxyalkyl group or a C₃-C₄-dihydroxyalkyl group; R2denotes hydrogen, a C₁-C₆-alkyl group, a C₂-C₄-hydroxyalkyl group, aphenyl group or an acetyl group; wherein at least one and at the mosttwo X1 to X3 groups denote C—R3, or C—R4 or C—R5, and at the most one ofthe X1 to X3 groups denotes sulfur, oxygen or N—R2.
 2. Agent accordingto claim 1, characterized in that X1 or X3 denotes sulfur, X2 denotesC—R4 and X3 denotes C—R5 or X1 denotes C—R3.
 3. Agent according to claim1, characterized in that X1 or X3 denote sulfur, X2 denotes C—R4 and X3denotes C—R5 or X1 denotes C—R3, and at least two of the R1, R3, R4 andR5 groups are hydrogen.
 4. Agent according to one of claims 1[sic-Translator], characterized in that the1,3-diamino-4-heteroarylbenzene derivative of formula (I) is selectedfrom among 1,3-diamino-4-(2-thiophenyl)benzene,1,3-diamino-4-(3-thiophenyl)benzene and the physiologically toleratedsalts thereof.
 5. Agent according to one of claims 1 to 4, characterizedin that it contains the 1,3-diamino-4-heteroarylbenzene of formula (I)in an amount from 0.005 to 20 wt. %.
 6. Agent according to one of claims1 to 5, characterized in that it has a pH from 6.5 to 11.5.
 7. Agentaccording to one of claims 1 to 6, characterized in that the developeris selected from the group consisting of 1,4-diaminobenzene,1,4-diamino-2-methylbenzene, 1,4-diamino-2,6-dimethylbenzene,1,4-diamino-3,5-diethylbenzene, 1,4-diamino-2,5-dimethylbenzene,1,4-diamino-2,3-dimethylbenzene, 2-chloro-1,4-diaminobenzene,1,4-diamino-2-(2-thiophenyl)benzene,1,4-diamino-2-(3-thiophenyl)benzene, 1,4-diamino-2-(3-pyridinyl)benzene,2,5-diaminobiphenyl, 1,4-diamino-2-methoxymethylbenzene,1,4-diamino-2-aminomethylbenzene, 1,4-diamino-2-hydroxymethylbenzene,1,4-diamino-2-(2-hydroxyethoxy)benzene, 1-(2,5-diaminophenyl)ethanol,2-[2-(acetylamino)ethoxy]-1,4-diaminobenzene, 4-phenylaminoaniline,4-dimethylaminoaniline, 4-diethylaminoaniline, 4-dipropylaminoaniline,4-[ethyl-(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]-2-methylaniline,4-[(2-methoxyethyl)amino]aniline, 4-[(3-hydroxypropyl)amino]aniline,4-[(2,3-dihydroxypropyl)amino]aniline,1,4-diamino-2-(2-hydroxyethyl)benzene,1,4-diamino-2-(1-methylethyl)benzene,1,3-bis[(4-amino-phenyl)(2-hydroxyethyl)amino]-2-propanol,1,4-bis[(4-aminophenyl)amino]butane,1,8-bis(2,5-diaminophenoxy)-3,6-di-oxaoctane, 4-aminophenol,4-amino-3-methylphenol, 4-amino-3-(hydroxymethyl)phenol,4-amino-3-fluorophenol, 4-methylaminophenol,4-amino-2-(aminomethyl)phenol, 4-amino-2-(hydroxymethyl)phenol,4-amino-2-fluorophenol, 4-amino-2-[(2-hydroxyethyl)amino]methylphenol,4-amino-2-methylphenol, 4-amino-2-(methoxymethyl)phenol,4-amino-2-(2-hydroxyethyl)phenol, 5-aminosalicylic acid,2,5-diaminopyridine, 2,4,5,6-tetraaminopyrimidine,2,5,6-triamino-4-(1H)-pyrimidone,4,5-diamino-1-(2-hydroxyethyl)-1H-pyrazole,4,5-diamino-1-(1-methylethyl)-1H-pyrazole,4,5-diamino-1-[(4-methylphenyl)methyl]-1H-pyrazole,1-[(4-chlorophenyl)methyl]-4,5-diamino-1H-pyrazole,4,5-diamino-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole [sic-Translator],2-aminophenol, 2-amino-6-methylphenol and 2-amino-5-methylphenol. 8.Agent according to one of claims 1 to 7, characterized in that thedevelopers and couplers are present in a total amount of 0.005 to 20 wt.%, based on the total amount of colorant,
 9. Agent according to one ofclaims 1 to 8, characterized in that it contains additionally at leastone direct dye.
 10. Agent according to one of claims 1 to 9,characterized in that it is a hair colorant. 11.1,3-Diamino-4-heteroarylbenzene derivatives of general formula (I)according to claim 1 under the condition that X2 does not stand fornitrogen when X1 stands for sulfur.